The region of Earth surrounding the equator is called the tropics.

Here's a more detailed explanation:

* Equator: An imaginary line that circles the Earth at 0 degrees latitude, dividing the Earth into the Northern and Southern Hemispheres.

* Tropics: The region between the Tropic of Cancer (23.5 degrees North) and the Tropic of Capricorn (23.5 degrees South). This area receives the most direct sunlight throughout the year, leading to warm temperatures and a tropical climate.

So, the tropics encompass the region surrounding the equator, extending outwards to about 23.5 degrees North and South.